A Thin Film Transistor (TFT) array substrate of a display device such as a Liquid Crystal Display (LCD) device and an Organic Light Emitting Diode Display (OLED) device usually includes a gate driving circuit, which provides a gate driving signal for the TFT array substrate. The gate driving circuit includes a plurality of stages of shift registers. In actual use, the level outputted from the shift register will be floating to a high voltage level before the scanning of the shift register, thus degrading the display performance of display device.